My 18 y.o. daughter was slightly flaring from mold exposure and then had to get the Covid booster. She is flaring VERY badly now. It started about 2 days after she received the booster. It has been almost 3 weeks now. We are pretty sure it is mast cell activation and are treating her with H1 and H2 blockers (Xyzal and Pepcid) and D-HIST Jr. Also, Histamine Block before meals. She is VERY slowly improving. Good info about MCAS: https://hoffmancentre.com/12-tips-living-mast-cell-activation-syndrome/ and from the same site: https://hoffmancentre.com/treatments/mcas/
She did pretty well after the first two shots, just a mild flare for a few days. I'm thinking things were bad this time because she had recently been exposed to mold, so her system was ramped up already.
We are all tripled vaxxed in our house, but I disagree with forcing people to get the shot to attend school, work, etc. People don't understand what PANS/PANDAS and MCAS people go through.